This invention relates to a vapor generating and recovering apparatus for vaporizing a liquid and condensing a vapor and more particularly relates to an improved safety control device to shut off the heating system for a vapor generating and recovering apparatus when the vapor exceeds a preselected level or an unsafe condition exists in the apparatus.
In the present state of the art, vapor generating and recovering devices for vaporizing and condensing a liquid are utilized in many different applications. For example, in the cleaning of objects such as metallic tools, plastic parts, and the like, hot or boiling solvents have been utilized to remove undesirable soluble and particulate matter from these tools, parts and the like by immersing the soiled object into hot or boiling solvent. In bringing the solvent to a boiling temperature, a solvent vapor zone is created above the boiling solvent solution in the tank or chamber in which objects may be placed for cleaning. The vaporized solvent is then subjected to cooling or condensing means and is recovered. Examples of this are set forth in U.S. Pat. No. 4,003,798 and U.S. Pat. No. 4,078,974. However, in vapor generating and recovery devices, it is frequently difficult for the cooling means to be sufficient to control the vapor level in the apparatus thereby creating possible hazardous conditions in the area around the apparatus.